Steering bent (triple tree/yoke replacement)

[tbone]

Hi everybody

Sorry for the long post

I am a newbie to motorcycle maintenance and modding but I bought a 1981 GS 650 GT recently. When I bought it I noticed the steering was slightly bent to one side. In my naivety I figured someone had probably dropped it before and had simply bent the handle bars. I replaced the handled bars and the steering is still bent. So I thought well what else could it be. I heard people saying your forks can get twisted in the triple tree and you need to untighten pinch bolts and ram wheel against a curb or rock backwards and forwards over the front end and this should untwist them, so I tried this but when tightening bolts back up it seemed to return to bent steering. I noticed that if I rotated the fork stanchions in the triple tree the wheel would bend to one side and then straighten so I realised the forks are bent, ran dti along them and sure enough they were, so have now got them straightened but the steering still appears to be bent. So I'm now thinking that that the triple tree/yoke must be bent.

So I'm thinking I need to replace the triple tree.
What models of GS will work on my 1981 GS650 GT (stanchions are 37mm)?
What other bikes triple trees would work on my GS?
Is it easy to use another bikes triple tree? or would it take more than just bolting on?
How would one go about measuring triple trees to see if they would fit my bike?
If the steering still seems bent after changing the triple tree what else could be wrong? headstock/frame?

When this situation occurs would the normal process of figuring out what it is be to as follows:
are the forks twisted in tree
are the handlebars straight
are the forks bent
is the triple tree bent
is the head stock bent/frame bent

Thanks for reading all that

 

[allojohn]

Before you do anything try loosening the whole front end then tighten from the wheel up.
If things are still out of alignment you may have bent forks/cracked trips.

 

[standswithabeer]

after loosening the triple tree bolts a little, did you rotate the forks and check that they are indeed now straight? that is to say, if the forks are in the usual location with the bolts just loose enough to allow rotation of the forks, did you spin them and see if the opposite ends swings in an arc? it shouldn't. you can also lower one fork down just enough to clear the upper triple and rotate it. it shouldn't wobble under the upper triple.

if the forks are indeed straight, try loosening the nut that allows the upper triple to swing side-to-side. at this point you should be able to slide both forks into both triples.

on a couple of my projects i've had to loosen the bolts as previously described to correct misalignment, by loosening the triple bolts a little and holding the wheel with my thighs. i then twist the bars. you may need to block under the engine to prevent the bike front dropping.